When he was sent onto the field, he received a warm reception from the crowd of 69,732 at Candlestick. Smith, the No 1 overall pick in the 2005 draft, has not always been so well-received by 49ers fans.

"It was great," Smith said. "It was humbling. It was very surreal.

"To go out there and get that kind of response was very cool. We've been through a lot, the fans and me. It made it almost that much sweeter. We've come a long way."

Said running back Frank Gore, "He deserved it. He had his ups and downs here. Last year, he had a great year and at the beginning of this year he was doing great. He got a chance to go out there and he deserved that."

But with any backup quarterback, Smith never knows when his number might be called next. Smith made his first appearance Sunday since exiting with a concussion Nov. 11. In his last full game, he completed 18 of 19 passes against the Cardinals on Oct. 29 and was named NFC Offensive Player of the Week.

But after being sidelined with a concussion, Smith never regained his starting job from Colin Kaepernick, whom Harbaugh tabbed as the starter for the remainder of the season. Now, it's Kaepernick who will lead the 49ers into the playoffs in two weeks.

"There's part of you that wants to go out and play, but it's a team sport," Smith said. "You swallow that part of it and be there for your team. I have a new role and I accept that role. Those are the things outside of my control. I do what I can to help this team win."

Smith needed seven pass attempts on Sunday to qualify for the NFL's passer rating crown with a 104.1 rating. Aaron Rodgers and Peyton Manning rank first and second at 108.0 and 105.9, respectively. Smith said there was never any discussion given to his getting the required pass attempts.